A hydraulic shield support is disclosed with at least two
adjustable-length hydraulic props supporting a dedicated shield, which
are connected through a control bank to a hydraulic fluid supply and
borne on base shoes, and to which a pressure in excess of the pressure of
the hydraulic fluid may be applied in the set condition of the shield
support. In order to provide almost any pressure level at each shield
support at a deep face in a simple way, the shield support has at least
one pressure intensifier located in a hydraulic pipe system between the
hydraulic fluid supply and the hydraulic props, with an oscillating
intensifier piston in the form a differential piston effecting the
increase in pressure. The low pressure inlet of the pressure intensifier
is connected to the setting pressure pipes upstream, and its
high-pressure outlet downstream, of a hydraulically-releasable non-return
valve.